import React from "react"; import ReactDOM from "react-dom"; import useForm from "react-hook-form"; function App() { const { register, handleSubmit } = useForm(); const onSubmit = data => { alert(JSON.stringify(data)); }; return (
{ if (e.target.value) { e.target.value = e.target.value.toUpperCase(); } }} placeholder="bill" ref={register} />
{ if (e.target.value) { e.target.value = e.target.value.toLowerCase(); } }} placeholder="luo" ref={register} />
{ const value = e.target.value; if (value.match(/^\d{2}$/) !== null) { e.target.value = value + "/"; } else if (value.match(/^\d{2}\/\d{2}$/) !== null) { e.target.value = value + "/"; } }} placeholder="12/12/1999" ref={register} />
); } const rootElement = document.getElementById("root"); ReactDOM.render(, rootElement);